Do VR Sensors have a polarity?????

myk · Post by **myk** » Mon Apr 02, 2007 7:35 pm

Ok

I got a v3.0 MS1 MSnSe and a random VR sensor.

Does it matter which wire goes to MS and which goes to ground??

Mike

slow_hemi6 · Post by **slow_hemi6** » Mon Apr 02, 2007 8:41 pm

Yes they do.
It has however to do with the direction of winding.Something not easy to see.
Connected with reverse polarity it will function but timming will drift with rpm.
This will probably be noticable with timing set to fixed in MT and watching the timing marks with a timing light and increasing revs.If this was to be the case then switch the wires and retest.Pick the connection with least drift.....
The technical point of this is you want to generate a positive 1/2 cylcle and then a negative 1/2 cycleand not the other way around.

PSIG · Post by **PSIG** » Wed Apr 04, 2007 7:48 am

An easy trick to test the VR wire polarity is with a volt meter. You can do this in the vehicle with a steel feeler gauge or a razor blade. Attach the meter to the VR wires. Slip the blade onto the front of the VR sensor. Watch the meter while you quickly yank the blade away from the sensor. You should see a small negative voltage pulse on the meter. If not, swap the leads.

Once you get the negative pulse, connect the sensor lead that is attached to the positive meter lead to Pin 24 on MS and the other to ground. If you have a shield or shield wire, only attach it at one end to ground also. With this configuration you should have VROUTINV jumpered to TSEL.

David